Systems And Methods For Implementing Optical And RF Communication Between Rotating And Stationary Components Of A Rotary Sensor System

ABSTRACT

Systems and methods are disclosed for implementing a rotary sensor system including rotating system components in RF signal and optical signal communication with stationary system components through a rotary coupler. The rotary coupler may be provided with an optical transmission line that passes inside or through the center of an inner conductor of a coaxial RF transmission line that itself extends across the rotational interface/s of the rotary coupler such that optical and RF signal energy may be provided simultaneously or otherwise across the rotary coupler using separate communication paths. A rotary sensor system may be further configured to convert multiple signals and/or types of signals to a common multiplexed optical signal stream for transmission together across an on-axis rotational optical interface of the rotary coupler.

RELATED APPLICATIONS

The present application is related in subject matter to concurrentlyfiled patent application Ser. No. ______ entitled “SYSTEMS AND METHODSFOR PROVIDING OPTICAL SIGNALS THROUGH A RF CHANNEL OF A ROTARY COUPLER”by Jones et al., which is incorporated herein by reference in itsentirety.

FIELD OF THE INVENTION

This invention relates generally to rotary sensor systems and moreparticularly to rotary sensor systems employing optical and RFcommunication between rotating and stationary components of a rotarysensor system.

BACKGROUND OF THE INVENTION

Radar and passive RF detection systems having one or more rotatingantennas are used in airborne, shipboard and ground based installations.The typical electrical interface to an antenna is one or more radiofrequency (RF) transmission line(s). In general, this type of systememploys a RF rotary coupler to interconnect the rotating antenna to theelectronics that remains stationary relative to the rotating antenna.Such rotary couplers are capable of providing radio frequency (RF)energy to and receiving RF energy from, the rotating antenna(s) throughone or more separate transmission lines or channels. A typical rotarycoupler with separate transmission lines has one coaxial transmissionline (RF channel 1) through which no other RF transmission lines pass.The remaining coaxial transmission lines (RF channels 2 and more) arearranged such that each additional transmission line is coaxial with theother transmission lines, and such that each given additionaltransmission line allows the other transmission lines to pass throughthe center of the given additional transmission line.

The rotating antenna assembly may also house sensor electronics tosupport a variety of different applications. The sensor electronics,housed in the rotating antenna assembly, require the bi-directional flowof data and/or control signals and these signals are typically passedthrough a rotary device which provides the interface to the stationaryplatform electronics.

Traditionally the data/control signal for sensor electronics, in arotating antenna application, is realized with a multi-circuit slip ringassembly. Multi-circuit slip ring assemblies are designed to passelectrical data/control signals. Some draw-backs with this technologyinclude the potential for a large number of circuits required to supportthe electronic bus architecture, potential bandwidth limitations inpassing data across a multi-circuit slip ring assembly and potential EMI(electromagnetic interference) concerns in high power RF applications.It is also not uncommon for certain applications, such as airborneinstallations, to have physical packaging constraints which will limitthe available volume for a slip ring installation which could limitsystem capability.

FIG. 1 is a cross sectional view of a conventional two channel radiofrequency (RF) rotary coupler assembly 100 having a stator portion 102and a mating rotor portion 104. Rotary coupler 100 is configured totransmit two RF channels, referred to as Channel 1 and Channel 2, acrossrotational interface/s of the coupler 100 that are formed between matingstator portion 102 and rotor portion 104 of the coupler 100. Channel 1is a RF channel transmitted on the central axis of rotary coupler 100and Channel 2 is a RF channel transmitted off of the central axis ofrotary coupler 100. As shown, a stationary coaxial signal input 113 isprovided on stator portion 102 for the RF signals of Channel 1, and astationary coaxial signal input 115 is provided on stator portion 102for the RF signals of Channel 2. Similarly, a rotating (rotor) coaxialsignal output 114 is provided on rotor portion 104 for the RF signals ofChannel 1, and a rotating (rotor) coaxial signal output 116 is providedon rotor portion 104 for the RF signals of Channel 2.

Still referring to FIG. 1, rotor portion 104 is rotationally guidedrelative to stator portion 102 by a pair of ball-bearing assemblies 144.Rotary coupler 100 is sealed to allow for control of the internalenvironment which is exposed to RF energy by, o-ring seals 145 betweenparts of the coupler that do not rotate relative to each other, and bywiper seals 146 provided between parts of the rotor 104 that rotaterelative to parts of the stator 102 of the rotary coupler 100. RF energyis conducted through Channel 1 of rotary coupler 100 by way of atransmission line formed between the surfaces of the internal cavities147 a and 147 b. RF energy is conducted through Channel 2 of rotarycoupler 100 by way of a transmission line with matching stub circuitsformed between the surfaces of internal cavities 148 a and 148 b.Between the rotor portion 104 and stator portion 102 of the rotarycoupler 100, RF energy of Channels 1 and/or 2 is made to pass byclose-fitting concentric cylindrical surfaces separated by a thin layerof dielectric material which form corresponding stepped impedance chokes117, 118, 119 and 120, between the rotor and stator portions 104 and 102of the rotary coupler 100.

As shown in FIG. 1, a coaxial transmission line is provided fortransmitting RF signals of Channel 1 between stationary coaxial signalinput 113 and rotating coaxial output 114, and a coaxial transmissionline is provided for transmitting RF signals of Channel 2 betweenstationary coaxial signal input 115 and rotating coaxial output 116.Specifically, a center conductor is provided for Channel 1 that includesa stationary on-axis inner conductor portion 122 in RF signalcommunication with a rotating on-axis inner conductor portion 121 acrossa rotational interface formed by close-fitting concentric cylindricalsurfaces of an innermost stepped impedance choke 117 that is locatedbetween the stationary portion 122 of the inner conductor of Channel 1and the adjacent rotating portion 121 of the inner conductor ofChannel 1. An outer conductor is formed for Channel 1 by steppedimpedance choke 118 that is located between the stationary portion 192of the outer conductor of Channel 1 and the adjacent rotation portion191 of the outer conductor of Channel 1. Similarly, a center conductoris provided for Channel 2 that includes a stationary off-axis innerconductor portion 192 in RF signal communication with a rotating coaxialinner conductor portion 191 across a rotational interface formed byclose-fitting concentric cylindrical surfaces of a stepped impedancechoke 120 that is located between the stationary portion 192 of theinner conductor of Channel 2 and the adjacent rotating portion 191 ofthe inner conductor of Channel 2. Similarly, an outer conductor isformed for Channel 2 by outermost stepped impedance choke 119 that islocated between the rotating portion 181 of the outer conductor ofChannel 2 and adjacent stationary portion 182 of the outer conductor ofChannel 2 and the bearing inner race support housing 125.

FIG. 2 is a partial enlarged view 200 of the stepped impedance choke 117of the rotary coupler assembly 100 of FIG. 1. As shown, the steppedimpedance choke 117 is formed between stationary on-axis inner conductorportion 122 of the Channel 1 transmission line and the rotating on-axisinner conductor portion 121 of the Channel 1 transmission line. Alsoshown, the stepped impedance choke 118 is formed between stationaryouter conductor portion 192 of the Channel 1 transmission line and therotating outer conductor portion 191 of Channel 1 transmission line.

SUMMARY OF THE INVENTION

Disclosed herein are systems and methods for transferring both opticaland RF energy through a rotary coupler. Using the disclosed systems andmethods, optical and RF energy may be provided simultaneously orotherwise across a rotary coupler using separate communication pathsthrough a coaxial transmission line that incorporates an on-axis fiberoptic transmission line, e.g., to simultaneously transfer opticalsignals and RF signals between a stationary and a rotating section of acoaxial transmission line that extends across rotational interface/s ofthe rotary coupler. The disclosed systems and methods may beadvantageously implemented in one exemplary embodiment to provide arotary coupler that interconnects components of a rotating assembly(e.g., rotating antenna assembly including any associated rotatingelectronics) in optical and RF signal communication with otherelectronics that remain stationary relative to the rotating assembly ofa given mobile or fixed platform (e.g., platform such as aircraft, ship,train, automobile, land installation such as radar station or satellitestation or control tower, etc.). Wherever the term “rotating” is usedherein to describe a given component it will be understood that such agiven component may be also be described as rotatable, i.e., configuredto rotate relative to a corresponding stationary component whether ornot actual rotation is occurring at any given time.

In one exemplary embodiment, a rotary coupler may be provided with anoptical transmission line (e.g., a single or multiple mode fiber opticline) that passes inside or through the center of an inner conductor ofa coaxial RF transmission line that itself extends across the rotationalinterface/s of the rotary coupler. In such an embodiment, both theoptical transmission line and the RF transmission line may be positionedat, or close to, the axis of rotation of the rotary coupler. In afurther embodiment, a rotary coupler may be provided that is configuredto transfer optical signals and multiple RF channels across therotational interface/s of a rotary coupler. In another exemplaryembodiment, a rotary coupler may be configured to transfer optical andRF energy across rotational interface/s of the rotary coupler using anoptical rotary joint positioned inside the inner conductor of a first RFchannel transmission line that itself is substantially centered at, andin line with, the rotational axis of the rotary coupler. When integratedinside or within an on-axis RF transmission line of a rotary coupler, anoptical transmission line may advantageously provide on-axis opticalsignal communication through the rotary coupler without adverselyimpacting or affecting the on-axis RF signal transmissions through therotary coupler. In a further embodiment, the optical rotary joint may bepositioned adjacent to a stepped impedance choke that is providedbetween the fixed and rotating portions of the inner conductor of thefirst RF channel transmission line.

In one exemplary embodiment, the disclosed systems and methods may beimplemented to convert multiple signals and/or types of signals (e.g.,RF signals, video signals, audio signals, control signals, data signals,computer network signals such as Ethernet, etc.) to a common multiplexedoptical signal stream that includes information from the various signalsfor transmission together across an on-axis rotational optical interface(e.g., optical rotary joint) of the rotary coupler. Such opticalcommunication may be bidirectional or unidirectional, and may occurthrough the inside of an on-axis RF transmission line thatsimultaneously transmits RF signals across the an on-axis rotationallyRF interface.

In one respect, disclosed herein is a rotary sensor system, including:rotatable system components including rotatable sensor electronics, atleast one rotatable RF sensor, and at least one rotatable optical signalcommunication component; stationary system components includingstationary RF sensor electronics for the at least one rotatable RFsensor, and at least one stationary optical signal communicationcomponent; and a rotary coupler coupled between the stationary systemcomponents and the rotatable system components, the rotary couplerhaving a stator portion rotatably coupled to a rotor portion. The statorportion may be coupled between the stationary system components and therotor portion, and the rotor portion may be coupled between therotatable system components and the stator portion such that the rotorportion rotates together with the rotatable system components relativeto the stator portion and the stationary system components. The statorportion may include a stationary RF conductor portion of a center RFtransmission line, and the rotor portion may include a rotatable RFconductor portion of the center RF transmission line, with the rotorportion being configured to rotate about a rotational axis relative tothe stator portion. The stationary RF conductor portion and therotatable RF conductor portion of the center RF transmission line may bedisposed in adjacent rotatable relationship to form a first part of acenter RF signal channel that extends across a rotational RF signalinterface defined between the stationary RF conductor portion and therotatable RF conductor portion of the center RF transmission line tocouple the at least one rotatable RF sensor in RF signal communicationwith the stationary RF sensor electronics. The stator portion mayfurther include a stationary optical conductor portion of an opticaltransmission line, and the rotor portion may further include a rotatableoptical conductor portion of the optical transmission line. Thestationary optical conductor portion and the rotatable optical conductorportion may be disposed in adjacent rotatable relationship to form anon-axis optical signal channel coincident with the rotational axis ofthe rotor portion and extending across a rotational optical signalinterface defined between the stationary optical conductor portion andthe rotatable optical conductor portion to couple the at least onestationary optical signal communication component in optical signalcommunication with at least one rotatable optical signal communicationcomponent. The rotational optical signal interface may be disposedwithin the center RF transmission line.

In another respect, disclosed herein is a method of operating a rotarysensor system, including the step of providing a rotary sensor system.The rotary sensor system may have rotatable system components includingrotatable sensor electronics, at least one rotatable RF sensor, and atleast one rotatable optical signal communication component. The rotarysensor system may also have stationary system components that includestationary RF sensor electronics for the at least one rotatable RFsensor, and at least one stationary optical signal communicationcomponent. A rotary coupler may be coupled between the stationary systemcomponents and the rotatable system components of the provided rotarysensor system. The rotary coupler may have a stator portion rotatablycoupled to a rotor portion, with the stator portion being coupledbetween the stationary system components and the rotor portion, and therotor portion being coupled between the rotatable system components andthe stator portion such that the rotor portion rotates together with therotatable system components relative to the stator portion and thestationary system components. The stator portion may include astationary RF conductor portion of a center RF transmission line, andthe rotor portion may include a rotatable RF conductor portion of thecenter RF transmission line, with the rotor portion being configured torotate about a rotational axis relative to the stator portion. Thestationary RF conductor portion and the rotatable RF conductor portionof the center RF transmission line may be disposed in adjacent rotatablerelationship to form a first part of a center RF signal channel thatextends across a rotational RF signal interface defined between thestationary RF conductor portion and the rotatable RF conductor portionof the center RF transmission line to couple the at least one rotatableRF sensor in RF signal communication with the stationary RF sensorelectronics. The stator portion may further include a stationary opticalconductor portion of an optical transmission line, and the rotor portionmay further include a rotatable optical conductor portion of the opticaltransmission line. The stationary optical conductor portion and therotatable optical conductor portion may be disposed in adjacentrotatable relationship to form an on-axis optical signal channelcoincident with the rotational axis of the rotor portion and extendingacross a rotational optical signal interface defined between thestationary optical conductor portion and the rotatable optical conductorportion to couple the at least one stationary optical signalcommunication component in optical signal communication with at leastone rotatable optical signal communication component. The rotationaloptical signal interface may be disposed within the center RFtransmission line, and the method may further include communicatingoptical signals between the at least one stationary optical signalcommunication component and the at least one rotatable optical signalcommunication component across the rotational optical signal interface.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a cross-sectional view of a conventional coaxial rotarycoupler.

FIG. 2 is a partial enlarged view from FIG. 1.

FIG. 3 is a cross sectional view of a rotary coupler assembly accordingto one exemplary embodiment of the disclosed systems and methods.

FIG. 4 illustrates a partial enlarged view from the embodiment of FIG.3.

FIG. 5 illustrates a partial enlarged view from the embodiment of FIG.3.

FIG. 6 illustrates a partial enlarged view from the embodiment of FIG.3.

FIG. 7 illustrates a partial enlarged view of stationary optical inputaccording to one exemplary embodiment of the disclosed systems andmethods.

FIG. 8 illustrates a partial exploded cross-sectional view of componentsof the embodiment of FIG. 3.

FIG. 9 illustrates an outer perspective view of the embodiment of FIG.3.

FIG. 10 illustrates an exploded perspective view of the embodiment ofFIG. 3.

FIG. 11 illustrates an exploded perspective view of an optical rotaryjoint assembly coupled to stationary fiber optic conductor portion androtating fiber optic conductor portion according to one exemplaryembodiment of the disclosed systems and methods.

FIG. 12 illustrates an exploded perspective view of an optical rotaryjoint assembly and rotating on-axis inner conductor coupler portionaccording to one exemplary embodiment of the disclosed systems andmethods.

FIG. 13 illustrates an exploded perspective view of an optical rotaryjoint assembly, rotating on-axis inner conductor coupler portion, andstationary on-axis inner conductor coupler portion according to oneexemplary embodiment of the disclosed systems and methods.

FIG. 14 illustrates an exploded perspective view of an assembled opticalrotary joint assembly, rotating on-axis inner conductor coupler portion,and stationary on-axis inner conductor coupler portion according to oneexemplary embodiment of the disclosed systems and methods.

FIG. 15 illustrates a simplified block diagram of optical signalcommunication components and electronic components of a rotary antennaarray system according to one exemplary embodiment of the disclosedsystems and methods.

DESCRIPTION OF ILLUSTRATIVE EMBODIMENTS

FIG. 3 is a cross sectional view of a combined multiple channel (in thisexample dual-channel) radio frequency (RF) and optical rotary couplerassembly 300 according to one exemplary embodiment of the disclosedsystems and methods. For further reference, FIG. 9 is an outerperspective view of the optical rotary coupler assembly 300 of FIG. 3.In the illustrated embodiment FIG. 3, rotary coupler 300 has a statorportion 352 and a mating rotor portion 354, and is configured totransmit an optical signal channel and two RF signal channels (referredto herein as RF channels 1 and 2) in a direction substantially parallelwith the longitudinal axis 350 of rotary coupler 300, and acrossrotational interface/s that are formed between mating stator portion 352and rotor portion 354 of coupler 300. It will be understood, however,that a combined RF and optical rotary coupler may alternatively beconfigured in other embodiments to similarly transmit an optical signalin combination with only one RF signal channel, or in combination withmore than two RF signal channels. In the illustrated embodiment of FIG.3, the optical signal channel is transmitted on the central axis ofrotary coupler 300 together with RF channel 1 which is also transmittedon the central axis of rotary coupler 300, with optical conductorportions 338 and 343 of the transmission line of the optical channelextending through the center of the inner RF conductor portions 384 and386 (including RF component coupler portions 324 and 326) of the on-axisRF channel 1. Also as shown, RF channel 2 is transmitted off of thecentral axis of rotary coupler 300.

Still referring to FIG. 3, a stationary RF signal input 325 (e.g.,coaxial connection) is provided on stator portion 352 of rotary coupler300 for the signals of RF Channel 1, and another stationary RF signalinput 328 (e.g., coaxial connection) is provided on stator portion 352of rotary coupler 300 for the signals of RF Channel 2. Similarly, arotating coaxial signal output 327 is provided on rotor portion 354 ofrotary coupler 300 for the signals of RF Channel 1, and a rotatingcoaxial signal output 329 is provided on rotor portion 354 of rotarycoupler 300 for the signals of RF Channel 2. As also shown, a stationaryoptical input 389 for a stationary fiber optic conductor portion 338 isprovided for the optical channel on stator portion 352 of rotary coupler300, and a rotating optical output 379 for a rotating fiber opticconductor portion 343 is provided for the optical channel on rotor 354of rotary coupler 300. Although the terms “input” and “output” are usedherein to refer to the stator and rotor portions of the rotary coupler300, it will be understood that RF and optical signal communicationacross the rotary coupler 300 may be bi-directional.

As shown, rotor portion 354 of RF coupler 300 is rotationally guidedrelative to stator portion 352 by, for example, ball-bearing assemblies304. Rotary coupler 300 may also be sealed to allow for control (e.g.,pressurization) of the internal environment which is exposed to RFenergy using o-ring seals 305 or any other suitable static seal betweenparts of the coupler that do not rotate relative to each other, andusing low-friction wiper seals 306 or other suitable dynamic sealbetween parts of the rotor 354 that rotate relative to parts of thestator 352 of the rotary coupler 300. RF energy is conducted throughChannel 1 of rotary coupler 300 by way of a transmission line formedbetween the surfaces of the internal cavities 370 a and 370 b of therotary coupler to contain RF energy. RF energy is conducted throughChannel 2 of rotary coupler 300 by way of a transmission line withmatching stub circuits formed between the surfaces of internal cavities371 a and 371 b. For example, RF energy of RF channels 1 and/or 2 may bemade to pass by close-fitting concentric cylindrical surfaces separatedby a thin layer of dielectric material which form corresponding steppedimpedance chokes 330, 331, and 332, between the rotor and statorportions 354 and 352 of the rotary coupler 300.

In the specific embodiment of FIG. 3, a coaxial transmission line isprovided for transmitting signals of RF Channel 1 between stationarycoaxial signal input 325 and rotating coaxial output 327, and a coaxialtransmission line is provided for transmitting signals of RF Channel 2between stationary coaxial signal input 328 and rotating coaxial output329. Specifically, a center conductor is provided for RF Channel 1 thatincludes a stationary on-axis inner conductor coupler portion 324 in RFsignal communication with a rotating on-axis inner conductor couplerportion 326 across a rotational interface formed by close-fittingconcentric cylindrical surfaces of an innermost stepped impedance choke330 that is positioned between the stationary conductor coupler portion324 of the inner conductor of RF Channel 1 and the adjacent rotatingconductor coupler portion 326 of the inner conductor of RF Channel 1.Similarly, an outer conductor may be formed for RF Channel 2 byoutermost stepped impedance choke 332 having close-fitting concentriccylindrical surfaces that may be provided as shown between the outerrotating conductor portion 392 of the outer conductor of RF Channel 2and adjacent outer stationary conductor portion 390 of the outerconductor of RF Channel 2 and the bearing inner housing 307 A middlestepped impedance choke 331 having close-fitting concentric cylindricalsurfaces may also be provided as shown between an inner rotatingconductor portion 398 and an outer stationary conductor portion 396 thattogether form part of the inner conductor of RF channel 2.

FIG. 4 illustrates a partial enlarged view 400 of innermost steppedimpedance choke 330 of FIG. 3. The stepped impedance choke 330 is formedby close-fitting concentric cylindrical surfaces separated by a thinlayer of dielectric material, i.e., between the inner surface of acylindrical aperture defined within outer stationary conductor couplerportion 324 of the inner conductor of RF Channel 1 transmission line anda corresponding cylindrical outer surface of the inner rotatingconductor coupler portion 326 of the inner conductor of RF Channel 1transmission line. Also shown in FIG. 4 are stationary fiber opticconductor portion 338 and rotating fiber optic conductor portion 343which are each received by an opposing end of a fiber optical rotaryjoint assembly 340 that includes mating stationary portion 333 androtating portion 334, and that is positioned inside the inner conductorof the RF channel 1 transmission line as shown in FIG. 3. Specifically,stationary fiber optic conductor portion 338 is received in stationaryportion 333 of fiber optical rotary joint assembly 340, and rotatingfiber optic conductor portion 343 is received in rotating portion 334 offiber optical rotary joint assembly 340 such that a terminal end ofstationary fiber optic conductor portion 338 is oriented in axialend-to-end adjacent facing relationship with a terminal end of rotatingfiber optic conductor portion 343 to create a rotational optical signalinterface 410. This configuration allows transmission of optical signalseither way across optical signal interface 410 between stationary fiberoptic conductor portion 338 and rotating fiber optic conductor portion343 at the same time that rotor portion 334 remains fixed or rotatestogether with rotating fiber optic conductor portion 343 relative tostator portion 333 and stationary fiber optic conductor portion 338.

It will be understood that the illustrated optical rotary joint assembly340 is exemplary only, and that any other configuration or opticalrotary joint assembly may be employed that is suitable for orienting andmaintaining a terminal end of a stationary fiber optic conductor portion338 in end-to-end adjacent facing relationship with a terminal end of arotating fiber optic conductor portion 343 in order to create arotational optical signal interface 410 across which optical signals maybe transmitted between stationary fiber optic conductor portion 338 androtating fiber optic conductor portion 343 at the same time that rotorportion 334 remains fixed or rotates together with rotating fiber opticconductor portion 343 relative to stator portion 333 and stationaryfiber optic conductor portion 338. Examples of suitable optical rotaryjoints include, but are not limited to, fiber optical rotary jointsavailable from Princetel of Hamilton, N.J.; Moog Components Group ofBlacksburg, Va. and Halifax Nova Scotia, Canada; and Schleifring ofFiirstenfeldbruck, Germany. In one particular exemplary embodiment, aPrincetel MJX10 Single-Channel FORJ may be employed.

FIG. 5 illustrates a partial enlarged view 500 from FIG. 3 of oneexemplary embodiment of stationary optical input 389 for stationaryfiber optic conductor portion 338 that may be provided for the opticalchannel on stator portion 352 of rotary coupler 300. As shown in FIG. 5,the stationary fiber optic conductor portion 338 spans a gap 323 createdbetween the stationary on-axis inner conductor portion 384 andstationary outer conductor 396 at an elbow 348 that is formed in the RFchannel 1 transmission line and that is configured at 90 degreesrelative to axis 350. However, it will be understood that a RF channel 1transmission line may be configured at any other angle greater or lessthan 90 degrees relative to axis 350 that is suitable for providing anentry point and creating a gap or other configuration that provides aninput for a stationary fiber optic conductor portion 338 into thestationary inner conductor 384 of the RF channel 1 transmission line. Asshown, the fiber-optic line exits through the wall of outer conductorportion 396 and in this case is supported by a strain relief fitting 341which may be sealed by, for example, a fixed environmental o-ring 345seal which is held in place by a retainer cap 342. It will be understoodthat in other embodiments it is possible that stationary fiber opticconductor portion 338 may be additionally or alternatively oriented atan angle relative to axis 350 to provide a suitable entry point forfiber optic conductor portion 338 into the stationary inner conductor384 of the RF channel 1 transmission line.

FIG. 6 illustrates a partial enlarged view 600 from FIG. 3 of oneexemplary embodiment of rotating optical output 379 for rotating fiberoptic conductor portion 343 that may be provided for the optical channelon rotor portion 354 of rotary coupler 300. As shown in FIG. 6, therotating fiber optic conductor portion 343 spans a gap 321 createdbetween the rotating on-axis inner conductor portion 386 and rotatingouter conductor 398 at an elbow 348 that is formed in the RF Channel 1transmission line and that is configured at 90 degrees relative to axis350. However, it will be understood that a RF Channel 1 transmissionline may be configured at any other angle greater or less than 90degrees relative to axis 350 that is suitable for providing an entrypoint and creating a gap or other configuration that provides an inputfor a rotating fiber optic conductor portion 343 into the rotating innerconductor 386 of the RF Channel 1 transmission line. As shown, thefiber-optic line exits through the wall of outer conductor portion 398and in this case is supported by a strain relief fitting 341 which maybe sealed by, for example, an o-ring 345 which is held in place by aretainer cap 342. It will be understood that in other embodiments it ispossible that rotating fiber optic conductor portion 343 may beadditionally or alternatively oriented at an angle relative to axis 350to provide a suitable entry point for rotating fiber optic conductorportion 343 into the rotating inner conductor 386 of the RF Channel 1transmission line.

FIG. 7 illustrates an alternative embodiment 700 of a stationary opticalinput 389 for stationary fiber optic conductor portion 338 that may beprovided for the optical channel on stator portion 352 of rotary coupler300. In this exemplary embodiment, stationary fiber optic conductorportion 338 is angled or oriented by an angle of about 25 degrees (e.g.,by an angle of about 20 to about 45 degrees in another exemplaryembodiment) relative to the RF conductor portions 384 and 396 of the RFtransmission line to span a gap 373 created between the outer stationaryconductor portion 396 and the stationary on-axis inner conductor portion384 of the RF channel 1 transmission line at a straight section 385 ofthe conductors 384 and 396 of the transmission line. Although notillustrated, it will be understood that a rotating optical output 379may be similarly provided and configured for the optical channel onrotor portion 354 of rotary coupler 300.

FIG. 8 illustrates an exploded cross-sectional view of components of theinner RF conductor of the on-axis RF channel 1 (including RF conductorportions 324 and 326), components of the optical conductor of theon-axis optical channel (including optical conductor portions 338 and343) and components of the fiber optical rotary joint assembly 340(including mating stationary portion 333 and rotating portion 334 of thefiber optical rotary joint assembly 340). For further reference, FIG. 10is an exploded perspective view of the optical rotary coupler assembly300 of FIG. 3. Referring now to FIGS. 3, 4, 8 and 10, fiber opticalrotary joint assembly 340 is dimensioned to be received and positionedinside a mating aperture 371 defined within the rotating on-axis innerconductor coupler portion 326 of the RF channel 1 transmission lineadjacent (or within or surrounded by) the stepped impedance choke 330formed between the stationary on-axis inner conductor coupler portion324 and rotating on-axis inner conductor coupler portion 326 of theinner conductor of the RF channel 1 transmission line. As further shownstationary RF conductor coupler portion 324 may be configured to haveany length suitable for extending between choke 330 and socket fitting339 that provides a coupled RF signal path between choke 330 andstationary RF input 325, and rotating RF conductor coupler portion 326may be configured to have any length suitable for extending betweenchoke 330 and socket fitting 339 that provides a coupled RF signal pathbetween choke 330 and rotating RF output 327.

As shown, an axially-oriented aperture is defined to extendlongitudinally through the stationary portion 333 of fiber opticalrotary joint assembly 340 and is dimensioned and configured to receivestationary fiber optic conductor portion 338 in a fixed relationshiprelative to stationary portion 333. Similarly, an axially-orientedaperture is defined to extend longitudinally through the rotatingportion 334 of the fiber optical rotary joint assembly 340 and isdimensioned and configured to receive the rotating fiber optic conductorportion 343 in fixed relationship relative to the rotating portion 334.As shown, when stationary portion 333 of fiber optical rotary jointassembly 340 is assembled with stationary fiber optic conductor portion338 and concentrically mated with rotating portion 334 of the fiberoptical rotary joint assembly 340 that is assembled with rotating fiberoptic conductor portion 343, optical conductor portions 338 and 343 areheld in close axially aligned relationship with each other such that theterminal end of stationary fiber optic conductor portion 338 ispositioned in axial end-to-end adjacent facing relationship with theterminal end of rotating fiber optic conductor portion 343 to create arotational optical signal interface 410. This configuration allowstransmission of optical signals across optical signal interface 410between stationary fiber optic conductor portion 338 and rotating fiberoptic conductor portion 343 at the same time that rotor portion 354 ofrotary coupler 300 rotates together with rotating fiber optic conductorportion 343 relative to stator portion 352 of rotary coupler 300 andstationary fiber optic conductor portion 338.

As previously described, the stationary fiber optic conductor portion338 spans a gap 323 created between the stationary on-axis innerconductor portion 384 and stationary outer conductor portion 396 of theRF channel 1 transmission line, and the rotating fiber optic conductorportion 343 spans a gap 321 created between the rotating on-axis innerconductor portion 386 and rotating outer conductor portion 398 of the RFchannel 1 transmission line.

In the illustrated embodiment, the stationary portion 333 of fiberoptical rotary joint assembly 340 may be prevented from rotatingrelative to stationary on-axis inner conductor coupler portion 324 ofthe RF channel 1 transmission line by virtue of a mechanicalinterference fit between these components, or by using any othersuitable mechanical assembly or configuration for holding these twocomponents in a fixed position relative to each other. At the same timeelectrical insulation may be maintained between the stationary on-axisinner conductor coupler portion 324 and rotating on-axis inner conductorcoupler portion 326 of the inner conductor of the RF channel 1transmission line by an anti-torque guide ring 335 of rigid dielectricmaterial (e.g., such as polytetrafluoroethylene (PTFE or Teflon) orother suitable dielectric material) disposed therebetween, and by usingclose-fitting anti-torque pins 336 which in this exemplary embodimentserve the purpose of proving a mechanical couple between stationaryon-axis inner conductor coupler portion 324 to anti-torque guide ring335 to stationary portion 333 of fiber optical rotary joint assembly 340for holding these three components in a fixed position relative to eachother. Anti-torque guide ring 335 may further be constrained fromrotation relative to the stationary on-axis inner conductor couplerportion 324 by frictional contact, and may thus serve to provide amechanical interference fit between the stationary portion 333 of fiberoptical rotary joint assembly 340 and stationary on-axis inner conductorcoupler portion 324 of the RF channel 1 transmission line to preventthese components from rotating relative to each other. In thisparticular embodiment, the rotating portion 334 of the fiber opticalrotary joint assembly 340 may be prevented from rotating relative to therotating on-axis inner conductor coupler portion 326 of the RF channel 1transmission line by virtue of mating close fitting flat surfaces 337 offiber optical rotary joint assembly 340 and flat surfaces 337 ofrotating on-axis inner conductor coupler portion 326, or by using anyother suitable mechanical assembly or configuration for holding thesetwo components in a fixed position relative to each other.

It will be understood that any suitable assembly or configuration ofcomponents may be employed to provide a stationary optical input for astationary fiber optic conductor portion 338, and to provide a rotatingoptical output for a rotating fiber optic conductor portion 343. Forexample, in the particular exemplary embodiment of FIG. 8 stationaryfiber optic conductor portion 338 may pass through the followingcomponents from the interior of rotary coupler 300 to the exteriorenvironment: stationary on-axis inner conductor portion 384, socketfitting 339, drilled set screw 353, and sealed strain-relief fitting 341and feed-through seal cover 342 in the form of “pig tail” cableconfiguration where the end of 338 is terminated with a suitable fiberoptic connector type. Similarly, in the exemplary embodiment of FIG. 8,rotating fiber optic conductor portion 343 may pass through thefollowing components from the interior of rotary coupler 300 to theexterior environment: rotating on-axis inner conductor portion 386 ofthe RF channel 1 transmission line, socket fitting 339, set screw 353,sealed fiber optic feed through strain-relief fitting 341, andfeed-through seal cover 342 in the form of “pig tail” cableconfiguration where the end of 343 is terminated with a suitable fiberoptic connector type. It will be understood that these particularcombinations of fiber optic conductor input and output components areexemplary only and that any other combination of components may beemployed.

Thus, as shown in the illustrated embodiments, one or more components ofan optical rotary joint may be provided within the on-axis inner(center) conductor portions of a RF channel of a rotary coupler forsupporting a on-axis optical signal channel conductor (fiber optic line)inside the on-axis inner RF conductor portions of the rotary coupler toallow for simultaneous transmission of RF and optical signals acrossrotational interfaces between rotor and stator portions of the rotarycoupler either during rotary coupler rotation or while the rotarycoupler rotor and stator components are fixed relative to each other. Astationary portion of the optical rotary joint may be configured toreceive a stationary fiber optic conductor portion that is fixed to thestator side of the rotary coupler and a mating rotation portion of theoptical rotary joint may be configured to receive a rotating fiber opticconductor portion that is fixed to the rotor side of the rotary coupler.The stationary portion of the optical rotary joint may be fixedlycoupled to the stator portion of the rotary coupler, and a matingrotating portion of the optical rotary joint may be fixedly coupled tothe rotor portion of the optical rotary joint. Optical inputs and/oroutputs for the optical channel conductors may be provided relative tothe inner RF conductors on each of the rotor or stator sides of therotary coupler, e.g., by angling either one or both of the inner RFconductor or optical signal channel conductor relative to the centralaxis of the rotary coupler (and relative to each other) such that theoptical signal channel conductor passes through a wall or other surfaceof the inner RF conductor to allow the optical fiber to transition frominside the inner RF conductor to a position outside the outer RFconductor.

FIG. 11 illustrates an exploded perspective view of a optical rotaryjoint assembly 340 coupled to stationary fiber optic conductor portion338 (e.g., single or multiple mode fiber optic conductor) and rotatingfiber optic conductor portion 343, and that is positioned for insertioninto mating aperture 371 defined within an inner channel couplercomponent 326 of the rotating on-axis inner conductor portion 386 of theRF channel 1 transmission line. As shown flat sides 337 are provided onthe outer surface of rotating portion 334 of rotary joint assembly 340to provide a rectangular-shaped profile which is configured to bereceived by a corresponding shaped square profile having two mating flatsurfaces within aperture 371 that prevent components 334 and 326 fromrotating relative to each other when they are assembled together asshown in FIG. 12.

FIG. 12 illustrates the inner channel coupler component 326 of therotating on-axis inner conductor portion 386 assembled around the rotaryjoint assembly 340 and fiber optic conductor portions 338 and 343. FIG.12 also shows dielectric guide ring 335 held in place between innerchannel coupler component 326 of the rotating on-axis inner conductorportion 386 and outer channel coupler component of the stationaryon-axis inner conductor coupler portion 324 by guide pins 336 (e.g.,stainless steel or other suitable material pins) that are dimensioned tobe received in corresponding openings in each sides of dielectric guidering 335, stationary portion 333 of rotary joint assembly 340, and outerchannel coupler component of the stationary on-axis inner conductorcoupler portion 324 to interlink these components in fixed relationshipwhen assembled together as shown in FIGS. 13 and 14.

FIG. 14 shows mating portions of stationary on-axis inner conductorcoupler portion 324 b and rotating on-axis inner conductor couplerportion 326 b aligned and configured for coupling to correspondingstationary inner channel coupler component 324 a and inner channelcoupler component 326 a, respectively, to complete the assembly of theinner conductor of the RF channel 1 transmission line which isdimensionally configured to be contained within cavity 370 b of rotarycoupler 300.

FIG. 15 illustrates a simplified block diagram of one exemplaryembodiment of optical signal communication components 1506 together withother exemplary electronic components of a rotary sensor systemconfigured in this case as a rotary antenna array system 1500. As shownin FIG. 15, a suite of sensors 1802, 1804,1806 and 1808 (e.g., antennaelement assemblies configured for different designated RF sensing tasks,or alternatively for electro-optic, infrared, etc. sensors) may bedeployed within open space within a rotating sensor assembly 1502. Inthis exemplary embodiment, rotating sensor assembly 1502 is described asa radome, however it will be understood that the disclosed systems andmethods may be implemented with any other type of rotating sensorassemblies including rotating sensor assemblies that are not enclosed.The RF output and/or input for sensors 1802 and 1804 is passed throughRF Rotary Coupler 300 with RF interface to connectors 327 and 329 housedwithin the radome 1502. Also shown in FIG. 15 are components of a systemsupport platform 1504 (e.g., mobile vehicular platform such as aircraft,ship, train, automobile, spacecraft; fixed land installation such asradar station or satellite station or control tower; etc.) that isdisposed in stationary (non-rotating) relationship relative to radome1502.

As shown in FIG. 15, system support platform 1504 of this embodimentincludes platform-side sensor electronics 1701, 1703, 1705, and 1707;and platform-side optical signal communication electronics 1510. In thisexemplary embodiment, platform-side sensor electronics 1701 and 1703interface to the RF Rotary Coupler 300 for exchanging RF signals 1732and 1733 with RF sensors 1802 and 1804 via respective RF input/outputs325/327 and 328/329. Also as illustrated in FIG. 15, optical controldata 1522 is generated by platform-side sensor electronics 1701 forsensor 1 (1802) and is passed through platform MUX/DEMUX circuitry 1510and optical rotary joint 340 of signal communication components 1506 toRadome MUX/DEMUX circuitry 1508 and sensor assembly-side electronics1601 for sensor 1 (1802). In this exemplary embodiment, electronics 1601is configured to provide control signals 1631 to control the pointingposition for the main beam of Sensor 1 (1802) based on the receivedoptical control signals 1522.

Still referring to FIG. 15, the sensor output and/or input signals 1735and 1737 of the given sensors 1806 and 1808 of radome 1502 may becoupled to other interfacing electronic circuit components 1603 and 1605that may include media converter circuitry (e.g., photonics link,Ethernet, RS422, etc.) that is configured to convert betweenelectron-based signals (e.g., RF signal or other signal format such asvideo signals, audio signals, control signals, data signals, computernetwork signals, etc.) of each radome sensor 1806 and 1808 or other typeof electronic circuitry and the corresponding optical photon-basedoptical signals 1524 and 1526 that are exchanged with radome MUX/DEMUXcircuitry 1508 as shown. Radome MUX/DEMUX circuitry 1508 is in turncoupled to multiplex/demultiplex and exchange (e.g., transmit and/orreceive) multiplexed optical signals corresponding to the opticalcontrol signals 1522 and optical sensor signals 1524, 1526 correspondingto the various different sensors 1802, 1806 and 1808 and/or other radomeelectronics with platform MUX/DEMUX circuitry 1510 across optical rotaryjoint assembly 340 of rotary coupler 300 via respective rotating andstationary optical conductor portions 343 and 338. In this regard,different optical signals may be multiplexed for simultaneouscommunication across single or multi mode fiber conductors 343 and 338in any suitable manner including, but not limited to, using wavelengthdivision multiplexing (WDM). Interfacing electronic components 1603 and1605 may be employed to accept sensor data from sensors 1806 and 1808 ina variety of different type formats (e.g., Ethernet, serial data, videodata, RF by a photonics link, etc.) and convert and communicate the dataof these sensor signals as photon-based optical signals 1524 and 1526 toradome MUX/DEMUX circuitry 1508.

As further shown in FIG. 15, platform MUX/DEMUX circuitry 1510 isprovided in communication with optical rotary joint assembly 340 and iscoupled to exchange multiplexed optical signals to and/or from radomeMUX/DEMUX circuitry 1508 across optical rotary joint assembly 340.Platform MUX/DEMUX circuitry 1510 is also coupled to multiplex,demultiplex, and exchange individual optical signals 1522, 1524 and 1526corresponding to platform-side sensor electronics 1701, 1705, and 1707as illustrated in FIG. 15. Examples of platform-side sensor electronics1701, 1705, and 1707 that may be employed to communicate with sensors1802, 1806 and 1808 via platform MUX/DEMUX circuitry 1510 and radomeMUX/DEMUX circuitry 1508 include, but are not limited to, receivers,controllers, drivers and/or processers for sensors 1802, 1806 and 1808.

It will be understood that the embodiment of FIG. 15 is exemplary only,and that any other configuration and/or type of optical communicationand other electronic components may be provided within a radome and/orplatform of a rotary antenna array system 1500, and further thatnon-multiplexed optical signals (e.g., from and/or to a single opticalsignal electronic circuit communication component) may alternatively becommunicated across an optical rotary joint assembly 340 of a rotaryantenna array system 1500 or other type of assembly that employs arotary coupler assembly 300 as described herein.

While the invention may be adaptable to various modifications andalternative forms, specific embodiments have been shown by way ofexample and described herein. However, it should be understood that theinvention is not intended to be limited to the particular formsdisclosed. Rather, the invention is to cover all modifications,equivalents, and alternatives falling within the spirit and scope of theinvention as defined by the appended claims. Moreover, the differentaspects of the disclosed systems and methods may be utilized in variouscombinations and/or independently. Thus the invention is not limited toonly those combinations shown herein, but rather may include othercombinations.

What is claimed is:
 1. A rotary sensor system, comprising: rotatable system components including rotatable sensor electronics, at least one rotatable RF sensor, and at least one rotatable optical signal communication component; stationary system components including stationary RF sensor electronics for the at least one rotatable RF sensor, and at least one stationary optical signal communication component; and a rotary coupler coupled between the stationary system components and the rotatable system components, the rotary coupler having a stator portion rotatably coupled to a rotor portion, the stator portion being coupled between the stationary system components and the rotor portion, and the rotor portion being coupled between the rotatable system components and the stator portion such that the rotor portion rotates together with the rotatable system components relative to the stator portion and the stationary system components; where the stator portion includes a stationary RF conductor portion of a center RF transmission line; where the rotor portion includes a rotatable RF conductor portion of the center RF transmission line, the rotor portion being configured to rotate about a rotational axis relative to the stator portion; where the stationary RF conductor portion and the rotatable RF conductor portion of the center RF transmission line are disposed in adjacent rotatable relationship to form a first part of a center RF signal channel that extends across a rotational RF signal interface defined between the stationary RF conductor portion and the rotatable RF conductor portion of the center RF transmission line to couple the at least one rotatable RF sensor in RF signal communication with the stationary RF sensor electronics; where the stator portion further comprises a stationary optical conductor portion of an optical transmission line, and where the rotor portion further comprises a rotatable optical conductor portion of the optical transmission line; where the stationary optical conductor portion and the rotatable optical conductor portion are disposed in adjacent rotatable relationship to form an on-axis optical signal channel coincident with the rotational axis of the rotor portion and extending across a rotational optical signal interface defined between the stationary optical conductor portion and the rotatable optical conductor portion to couple the at least one stationary optical signal communication component in optical signal communication with at least one rotatable optical signal communication component; and where the rotational optical signal interface is disposed within the center RF transmission line.
 2. The rotary sensor system of claim 1, further comprising: a rotatable sensor assembly configured as a radome that houses at least a portion of the rotatable system components, the rotatable sensor assembly being coupled to rotate with the rotor portion of the rotary coupler; and a system support platform supporting at least portion of the stationary system components thereon, the system support platform being coupled to remain stationary with the stator portion of the rotary coupler.
 3. The rotary sensor system of claim 2, where the system support platform is a mobile system support platform; and where the rotatable sensor assembly is a rotatable sensor array.
 4. The rotary sensor system of claim 3, where the system support platform is an aircraft.
 5. The rotary sensor system of claim 1, further comprising: an optical rotary joint disposed within the center RF transmission line of the rotary coupler; where the stationary optical conductor portion comprises a stationary fiber optic portion; where the rotatable optical conductor portion comprises a rotatable fiber optic portion; where a terminal end of the stationary fiber optic conductor portion is positioned in axial end-to-end adjacent facing relationship with a terminal end of the rotatable fiber optic conductor portion within the optical rotary joint to form the rotational optical signal interface within the optical rotary joint between the stationary fiber conductor portion and the rotatable fiber optic conductor portion; and where the rotational optical signal interface is configured to pass optical signals between the stationary optical conductor portion and the rotatable optical conductor portion to communicate optical signals between the at least one stationary optical signal communication component and the at least one rotatable optical signal communication component while the rotatable sensor assembly and rotor portion of the rotary coupler are both stationary and rotating relative to the system support platform and stator portion of the rotary coupler.
 6. The rotary sensor system of claim 5, where: the stationary optical conductor portion and the rotatable optical conductor portion of the rotary coupler comprise respective optical fiber conductors that are disposed in adjacent rotatable relationship to form an on-axis optical signal channel; the rotatable system components comprise multiple optical signal sources coupled to the rotatable optical signal communication component; the rotatable optical signal communication component comprises optical multiplexer and demultiplexer circuitry coupled between the multiple optical signal sources and the rotatable optical conductor portion of the on-axis optical signal channel; the stationary system components comprise multiple stationary sensor electronic components coupled to the rotatable optical signal communication component; the stationary optical signal communication component comprises optical multiplexer and demultiplexer circuitry coupled between the multiple stationary sensor electronic components and the rotatable optical conductor portion of the on-axis optical signal channel; and the rotatable optical multiplexer and demultiplexer circuitry and the stationary optical multiplexer and demultiplexer circuitry are configured to cooperate to multiplex and demultiplex individual optical signals so as to simultaneously exchange individual optical signals across the on-axis optical signal channel between respective individual rotatable optical signal sources and corresponding stationary sensor electronic components while the rotatable sensor assembly and rotor portion of the rotary coupler are both stationary and rotating relative to the system support platform and stator portion of the rotary coupler.
 7. The rotary sensor system of claim 5, where the stator portion further comprises a stationary RF conductor portion of a first concentric RF transmission line that is concentrically disposed around the center RF transmission line; where the rotor portion further comprises a rotatable RF conductor portion of a first concentric RF transmission line that is concentrically disposed around the center RF transmission line; where the stationary RF conductor portion and the rotatable RF conductor portion of the first concentric RF transmission line are disposed in adjacent rotatable relationship to form a second part of the center RF signal channel that extends across a rotational RF signal interface defined between the stationary RF conductor portion and the rotatable RF conductor portion of the first concentric RF transmission line to couple the at least one rotatable RF sensor in RF signal communication with the stationary RF sensor electronics; where the stationary RF conductor portion of the center RF transmission line further comprises a stationary center conductor coupler portion; and where the rotatable RF conductor portion of the center RF transmission line further comprises a rotatable center conductor coupler portion received in rotatable concentric relationship with the stationary center conductor coupler portion to form the rotational RF signal interface of the center RF transmission line between concentric-fitting surfaces of the stationary RF conductor portion and the rotatable RF conductor portion of the center RF transmission line, the rotational RF signal interface being formed around the optical rotary joint.
 8. The rotary sensor system of claim 7, where: the stationary optical conductor portion and the rotatable optical conductor portion of the rotary coupler comprise respective optical fiber conductors that are disposed in adjacent rotatable relationship to form an on-axis optical signal channel; the rotatable system components comprise multiple optical signal sources coupled to the rotatable optical signal communication component; the rotatable optical signal communication component comprises optical multiplexer and demultiplexer circuitry coupled between the multiple optical signal sources and the rotatable optical conductor portion of the on-axis optical signal channel; the stationary system components comprise multiple stationary sensor electronic components coupled to the rotatable optical signal communication component; the stationary optical signal communication component comprises optical multiplexer and demultiplexer circuitry coupled between the multiple stationary sensor electronic components and the rotatable optical conductor portion of the on-axis optical signal channel; and the rotatable optical multiplexer and demultiplexer circuitry and the stationary optical multiplexer and demultiplexer circuitry are configured to cooperate to multiplex and demultiplex individual optical signals so as to simultaneously exchange individual optical signals across the on-axis optical signal channel between respective individual rotatable optical signal sources and corresponding stationary sensor electronic components.
 9. The rotary sensor system of claim 7, where: the rotatable system components further comprise at least one additional rotatable RF sensor, and the stationary system components further comprise stationary RF sensor electronics for the at least one additional rotatable RF sensor; the stator portion further comprises a stationary RF conductor portion of a second concentric RF transmission line that is concentrically disposed around the first concentric RF transmission line; the rotor portion further comprises a rotatable RF conductor portion of a second concentric RF transmission line that is concentrically disposed around the first concentric RF transmission line; the stationary RF conductor portion and the rotatable RF conductor portion of the first concentric RF transmission line are disposed in adjacent rotatable relationship to form a first part of a concentric RF signal channel that extends across a rotational RF signal interface defined between the stationary RF conductor portion and the rotatable RF conductor portion of the first concentric RF transmission line to couple the at least one additional rotatable RF sensor in RF signal communication with the RF processing circuitry of the system support platform; and the stationary RF conductor portion and the rotatable RF conductor portion of the second concentric RF transmission line are disposed in adjacent rotatable relationship to form a second part of the concentric RF signal channel that extends across a rotational RF signal interface defined between the stationary RF conductor portion and the rotatable RF conductor portion of the second concentric RF transmission line.
 10. The rotary sensor system of claim 9, where: the stationary optical conductor portion and the rotatable optical conductor portion of the rotary coupler comprise respective optical fiber conductors that are disposed in adjacent rotatable relationship to form an on-axis optical signal channel; the rotatable system components comprise multiple optical signal sources coupled to the rotatable optical signal communication component; the rotatable optical signal communication component comprises optical multiplexer and demultiplexer circuitry coupled between the multiple optical signal sources and the rotatable optical conductor portion of the on-axis optical signal channel; the stationary system components comprise multiple stationary sensor electronic components coupled to the rotatable optical signal communication component; the stationary optical signal communication component comprises optical multiplexer and demultiplexer circuitry coupled between the multiple stationary sensor electronic components and the rotatable optical conductor portion of the on-axis optical signal channel; and the rotatable optical multiplexer and demultiplexer circuitry and the stationary optical multiplexer and demultiplexer circuitry are configured to cooperate to multiplex and demultiplex individual optical signals so as to simultaneously exchange individual optical signals across the on-axis optical signal channel between respective individual rotatable optical signal sources and corresponding stationary sensor electronic components.
 11. A method of operating a rotary sensor system, comprising: providing a rotary sensor system comprising: rotatable system components including rotatable sensor electronics, at least one rotatable RF sensor, and at least one rotatable optical signal communication component, stationary system components including stationary RF sensor electronics for the at least one rotatable RF sensor, and at least one stationary optical signal communication component, and a rotary coupler coupled between the stationary system components and the rotatable system components, the rotary coupler having a stator portion rotatably coupled to a rotor portion, the stator portion being coupled between the stationary system components and the rotor portion, and the rotor portion being coupled between the rotatable system components and the stator portion such that the rotor portion rotates together with the rotatable system components relative to the stator portion and the stationary system components. where the stator portion includes a stationary RF conductor portion of a center RF transmission line, where the rotor portion includes a rotatable RF conductor portion of the center RF transmission line, the rotor portion being configured to rotate about a rotational axis relative to the stator portion, where the stationary RF conductor portion and the rotatable RF conductor portion of the center RF transmission line are disposed in adjacent rotatable relationship to form a first part of a center RF signal channel that extends across a rotational RF signal interface defined between the stationary RF conductor portion and the rotatable RF conductor portion of the center RF transmission line to couple the at least one rotatable RF sensor in RF signal communication with the stationary RF sensor electronics, where the stator portion further comprises a stationary optical conductor portion of an optical transmission line, and where the rotor portion further comprises a rotatable optical conductor portion of the optical transmission line, where the stationary optical conductor portion and the rotatable optical conductor portion are disposed in adjacent rotatable relationship to form an on-axis optical signal channel coincident with the rotational axis of the rotor portion and extending across a rotational optical signal interface defined between the stationary optical conductor portion and the rotatable optical conductor portion to couple the at least one stationary optical signal communication component in optical signal communication with at least one rotatable optical signal communication component, and where the rotational optical signal interface is disposed within the center RF transmission line; and where the method further comprises communicating optical signals between the at least one stationary optical signal communication component and the at least one rotatable optical signal communication component across the rotational optical signal interface.
 12. The method of claim 11, where the rotary system further comprises a rotatable sensor assembly configured as a radome that houses at least a portion of the rotatable system components, the rotatable sensor assembly being coupled to rotate with the rotor portion of the rotary coupler; and a system support platform supporting at least portion of the stationary system components thereon, the system support platform being coupled to remain stationary with the stator portion of the rotary coupler.
 13. The method of claim 12, where the system support platform is a mobile system support platform; and where the rotatable sensor assembly is a rotatable sensor array.
 14. The method of claim 13, where the system support platform is an aircraft.
 15. The method of claim 11, where the rotary system further comprises an optical rotary joint disposed within the center RF transmission line of the rotary coupler; where the stationary optical conductor portion comprises a stationary fiber optic portion; where the rotatable optical conductor portion comprises a rotatable fiber optic portion; where a terminal end of the stationary fiber optic conductor portion is positioned in axial end-to-end adjacent facing relationship with a terminal end of the rotatable fiber optic conductor portion within the optical rotary joint to form the rotational optical signal interface within the optical rotary joint between the stationary fiber conductor portion and the rotatable fiber optic conductor portion; and where the method further comprises: passing optical signals between the stationary optical conductor portion and the rotatable optical conductor portion to communicate optical signals between the at least one stationary optical signal communication component and the at least one rotatable optical signal communication component while the rotatable sensor assembly and rotor portion of the rotary coupler are both stationary and rotating relative to the system support platform and stator portion of the rotary coupler.
 16. The method of claim 15, where the stationary optical conductor portion and the rotatable optical conductor portion of the rotary coupler comprise respective optical fiber conductors that are disposed in adjacent rotatable relationship to form an on-axis optical signal channel; where the rotatable system components comprise multiple optical signal sources coupled to the rotatable optical signal communication component; where the rotatable optical signal communication component comprises optical multiplexer and demultiplexer circuitry coupled between the multiple optical signal sources and the rotatable optical conductor portion of the on-axis optical signal channel; where the stationary system components comprise multiple stationary sensor electronic components coupled to the rotatable optical signal communication component; where the stationary optical signal communication component comprises optical multiplexer and demultiplexer circuitry coupled between the multiple stationary sensor electronic components and the rotatable optical conductor portion of the on-axis optical signal channel; and where the method further comprises: using the rotatable optical multiplexer and demultiplexer circuitry and the stationary optical multiplexer and demultiplexer circuitry in a cooperative manner to multiplex and demultiplex individual optical signals so as to simultaneously exchange individual optical signals across the on-axis optical signal channel between respective individual rotatable optical signal sources and corresponding stationary sensor electronic components while the rotatable sensor assembly and rotor portion of the rotary coupler are both stationary and rotating relative to the system support platform and stator portion of the rotary coupler.
 17. The method of claim 15, where the stator portion further comprises a stationary RF conductor portion of a first concentric RF transmission line that is concentrically disposed around the center RF transmission line; where the rotor portion further comprises a rotatable RF conductor portion of a first concentric RF transmission line that is concentrically disposed around the center RF transmission line; where the stationary RF conductor portion and the rotatable RF conductor portion of the first concentric RF transmission line are disposed in adjacent rotatable relationship to form a second part of the center RF signal channel that extends across a rotational RF signal interface defined between the stationary RF conductor portion and the rotatable RF conductor portion of the first concentric RF transmission line to couple the at least one rotatable RF sensor in RF signal communication with the stationary RF sensor electronics; where the stationary RF conductor portion of the center RF transmission line further comprises a stationary center conductor coupler portion; where the rotatable RF conductor portion of the center RF transmission line further comprises a rotatable center conductor coupler portion received in rotatable concentric relationship with the stationary center conductor coupler portion to form the rotational RF signal interface of the center RF transmission line between concentric-fitting surfaces of the stationary RF conductor portion and the rotatable RF conductor portion of the center RF transmission line, the rotational RF signal interface being formed around the optical rotary joint; and where the method further comprises: passing first RF signals across the center RF signal channel between the at least one rotatable RF sensor and the stationary RF sensor electronics for the least one rotatable RF sensor while the rotor portion of the rotary coupler is both stationary and rotating relative to the stator portion of the rotary coupler.
 18. The method of claim 17, where the stationary optical conductor portion and the rotatable optical conductor portion of the rotary coupler comprise respective optical fiber conductors that are disposed in adjacent rotatable relationship to form an on-axis optical signal channel; where the rotatable system components comprise multiple optical signal sources coupled to the rotatable optical signal communication component; where the rotatable optical signal communication component comprises optical multiplexer and demultiplexer circuitry coupled between the multiple optical signal sources and the rotatable optical conductor portion of the on-axis optical signal channel; where the stationary system components comprise multiple stationary sensor electronic components coupled to the rotatable optical signal communication component; where the stationary optical signal communication component comprises optical multiplexer and demultiplexer circuitry coupled between the multiple stationary sensor electronic components and the rotatable optical conductor portion of the on-axis optical signal channel; and where the method further comprises: using the rotatable optical multiplexer and demultiplexer circuitry and the stationary optical multiplexer and demultiplexer circuitry in a cooperative manner to multiplex and demultiplex individual optical signals so as to simultaneously exchange individual optical signals across the on-axis optical signal channel between respective individual rotatable optical signal sources and corresponding stationary sensor electronic components while the rotor portion of the rotary coupler is both stationary and rotating relative to the stator portion of the rotary coupler.
 19. The method of claim 17, where the rotatable system components further comprise at least one additional rotatable RF sensor, and the stationary system components further comprise stationary RF sensor electronics for the at least one additional rotatable RF sensor; the stator portion further comprises a stationary RF conductor portion of a second concentric RF transmission line that is concentrically disposed around the first concentric RF transmission line; where the rotor portion further comprises a rotatable RF conductor portion of a second concentric RF transmission line that is concentrically disposed around the first concentric RF transmission line; where the stationary RF conductor portion and the rotatable RF conductor portion of the first concentric RF transmission line are disposed in adjacent rotatable relationship to form a first part of a concentric RF signal channel that extends across a rotational RF signal interface defined between the stationary RF conductor portion and the rotatable RF conductor portion of the first concentric RF transmission line to couple the at least one additional rotatable RF sensor in RF signal communication with the RF processing circuitry of the system support platform; where the stationary RF conductor portion and the rotatable RF conductor portion of the second concentric RF transmission line are disposed in adjacent rotatable relationship to form a second part of the concentric RF signal channel that extends across a rotational RF signal interface defined between the stationary RF conductor portion and the rotatable RF conductor portion of the second concentric RF transmission line; and where the method further comprises: passing additional RF signals across the concentric RF signal channel between the at least one additional rotatable RF sensor and the stationary RF sensor electronics for the at least one additional rotatable RF sensor while the rotor portion of the rotary coupler is both stationary and rotating relative to the stator portion of the rotary coupler.
 20. The method of claim 19, where the stationary optical conductor portion and the rotatable optical conductor portion of the rotary coupler comprise respective optical fiber conductors that are disposed in adjacent rotatable relationship to form an on-axis optical signal channel; where the rotatable system components comprise multiple optical signal sources coupled to the rotatable optical signal communication component; where the rotatable optical signal communication component comprises optical multiplexer and demultiplexer circuitry coupled between the multiple optical signal sources and the rotatable optical conductor portion of the on-axis optical signal channel; where the stationary system components comprise multiple stationary sensor electronic components coupled to the rotatable optical signal communication component; where the stationary optical signal communication component comprises optical multiplexer and demultiplexer circuitry coupled between the multiple stationary sensor electronic components and the rotatable optical conductor portion of the on-axis optical signal channel; and where the method further comprises: using the rotatable optical multiplexer and demultiplexer circuitry and the stationary optical multiplexer and demultiplexer circuitry in a cooperative manner to multiplex and demultiplex individual optical signals so as to simultaneously exchange individual optical signals across the on-axis optical signal channel between respective individual rotatable optical signal sources and corresponding stationary sensor electronic components. 